Heretofore, a connector, which electrically connects circuit boards to each other, has been known (refer to Patent Literature 1). That is to say, a header mounted on one of the circuit boards and a socket mounted on the other circuit board are fitted to each other, whereby contacts corresponding thereto are brought into contact with and conducted to each other, and conductor patterns of the circuit boards to which the respective contacts are connected are electrically connected to each other. Holding fixtures of the header are soldered to the circuit board, whereby bonding strength between the header and the circuit board is enhanced.